Alcohol and faulty equipment are suspected as contributing causes to a late Sunday morning accident on Route 31 that injured four people and shut down the roadway for more than three hours.

St. Charles police, in a press release, said Luis Pina, of the 400 block of New York Street, Aurora, was southbound on Route 31, just north of Wildrose Springs Drive, when he lost control of his Pontiac Grand Am and went into oncoming traffic. The Grand Am collided with a northbound Chevrolet Tahoe driven by Manuel Nunez, of the 70 block of West Old Indian Trail Road, Aurora.

The accident occurred shortly before 11 a.m.

St. Charles police and fire vehicle responded to the crash, which required extrication of Pina from his vehicle. The roadway was shut down during the incident, police said.

Pina was transported to Delnor Hospital, and Nunez and his two passengers also were transported there for treatment, the release states.

Alcohol and faulty equipment are suspected as contributing causes to Pina losing control of his vehicle, the release states. Police reopened Route 31 at 2:15 p.m.

The accident remains under investigation.